How do you build a glass greenhouse?

Build a glass greenhouse that uses recycled wood windows by planning the structure, leveling the ground, installing a foundation, creating a weed-free floor, and installing the glass. The process requires several weekends to complete.

1. Gather old wood windows

   Collect wood windows with the glass intact from demolition projects. Ask before removing any materials. If windows have one or more panes missing, replace them.

2. Create the design

   Inventory the windows you collect, and list their sizes. Use graph paper to create an appropriate design. Design one wall higher than the others so the structure sheds rain.

3. Level the ground

   Mark the location of the new greenhouse with stakes. Tie twine between the stakes to mark the area. Add or remove soil as necessary to level the ground. Remove the twine and stakes.

4. Build a foundation

   Dig postholes at each of the four corners and install pressure-treated posts, leaving 6 inches above the ground. Attach pressure-treated 2-by-6-inch boards to form the foundation of the greenhouse. Add concrete to the postholes, and trim the posts.

5. Ensure a weed-free floor

   Cover the area inside the foundation with weed-blocking cloth. Cover the cloth with pea gravel.

6. Build the walls

   Use the windows to create walls on three sides of the greenhouse. Use taller windows on one side to create a sloping roof. Use additional windows to create the roof. Cover the triangular opening at the end of the structure using plastic sheeting. Attach a tarp to the other end to create a door.